AFTER THE GREATEST 11-YEAR OPENING A HITTER HAS EVER HAD, ALBERT PUJOLS IS STARTING OVER WITH THE ANGELS. HOW CAN HIS NEXT DECADE POSSIBLY MATCH UP WITH THE LAST? IT ALL STARTS WITH A DAILY SEARCH FOR THE PERFECT SWING

The fans wore orange shirts and the little kids sported faux-hawks, and they lined up two deep along the chain-link fence behind the rightfield wall at Scottsdale Stadium, craning their necks for a glimpse of what was happening in the bullpens beneath the bleachers. It was the morning of Feb. 19, the first workout for Giants pitchers and catchers. The catchers were in the midst of a typical drill: They received pitches, then sprang to their feet as if to gun down a base stealer at second. With each pop of the mitt, the fans shouted encouragement and raised their arms to take blurry snaps on their phones. That was because one of the catchers participating in the drill, looking more explosive than anyone else, was 24-year-old Buster Posey.

Posey does not yet have a full regular season's worth of games on his major league résumé—he has played in 160—but he has already accumulated a career's worth of experiences, for better and worse. As a rookie in 2010 he hit .305 with 18 home runs, and was a key player in the Giants' first world championship in 56 years. Then, last May 25, Marlins outfielder Scott Cousins plowed into him on a play at the plate, fracturing Posey's left leg, tearing ligaments in his ankle and ending his season. On that cool morning in Scottsdale, nine months later, Posey's catching—and his powerful batting practice display ("Four-seam coming at 55, it's not tough to square it up," Posey would humbly say)—suggested something of extreme importance for the Giants. As one particularly sonorous fan screamed at Posey, "You're back, baby!"

Manager Bruce Bochy confirmed that sentiment. "He looks like he's over it," Bochy said. "He's healed." So, too, are the Giants, whose dreams of an NL West title repeat were shattered along with their smooth-cheeked leader's leg. San Francisco's 12-deep pitching staff—which ranked second in the majors in both starters' ERA (3.28) and relievers' ERA (3.02)—kept them competitive for a while in 2011. Eventually, though, the absence of Posey—who, according to baseball-reference.com, was worth more than three wins (roughly the value of an All-Star) as a rookie despite playing just 108 games—caught up with them. After being in first place as late as Aug. 9, they finished eight games behind the first-place Diamondbacks. The key for the Giants this season? "It's obvious to everybody, inside or outside the organization," says G.M. Brian Sabean. "Buster needs to return to form."

Posey must recapture the precocious poise he showed in directing a bearded, long-haired, tattooed, excitable pitching staff. Sabean admits the group is "kind of eccentric, individually and collectively," but Posey had already commanded their respect in his rookie season. "He doesn't have a problem talking to me as if I'm just another f------ rookie kid, which is refreshing," says ace—and longhair—Tim Lincecum, the 27-year-old two-time Cy Young winner.

Just as essential will be what Posey does at the plate, not behind it. Without their cleanup hitter for the majority of the season, the Giants ranked last in the NL in runs scored, squeezing out just 3.5 per game. That average fell to 2.7 during an 11--18 August, when they dropped eight games in the standings. Sabean didn't acquire a power bat in the off-season, trading instead for outfielders Melky Cabrera and Angel Pagan. Bochy describes the pair as "nice players, catalyst-type guys"—in other words, they're not exactly mashers. Sabean's off-season strategy was in part dictated by his desire to return his pitching staff more or less intact, and to save funds in the hope of signing Lincecum (free agent after the 2013 season) and 27-year-old No. 2 starter Matt Cain (free agent after this season)to long-term extensions. It was also dictated by the prospect of Posey's return to the lineup.

While Posey proved to be the NL West's most irreplaceable loss in 2011, he isn't the division's only such player. "There are some guys that you absolutely know make or break a team," says Padres closer Huston Street, who was traded from the Rockies in December. "Whether that's an energy, whether that's their spot in the lineup, whether that's being a catcher, a shortstop, a centerfielder."

The others—Colorado shortstop Troy Tulowitzki, Dodgers centerfielder Matt Kemp and Diamondbacks rightfielder Justin Upton—are all, like Posey, short on years (Kemp is the oldest, at 27) and long on futures. "I think we might have a few in this division that are once in a generation players," says Tulowitzki, not entirely illogically. No other division has been as wide-open in recent years as the NL West, which, unlike the other five, has sent each of its clubs to the playoffs at least once since 2006. And in no other division do teams' fates hinge on the performances of so few. "Those four players really represent the best four players at their positions in the National League," says Rockies G.M. Dan O'Dowd. Call them the Unexpendables.

This winter the NL West's general managers undertook disparate strategies to build around those players. O'Dowd endeavored to acquire productive players who could also lessen the leadership burden on his shortstop, who for the second consecutive season was an All-Star, an MVP vote-getter, and a Gold Glove and Silver Slugger winner. That meant adding older pieces, like versatile free agent Michael Cuddyer and righthander Jeremy Guthrie, both 32; second baseman Marco Scutaro, 36, and catcher Ramon Hernandez, 35; third baseman Casey Blake, 38; and even signing 49-year-old southpaw Jamie Moyer out of retirement.

While Tulowitzki is revered in the Rockies' clubhouse, last season even he found the sheriff role beyond him. The Rockies, a preseason favorite, are certain that a discordant clubhouse culture contributed to their disappointing 73--89 record. "We had so many young guys that it became somewhat of a distraction that we didn't have [experienced] guys to go to," Tulowitzki says. "I was still young and I was considered the leader, but I hadn't been through all the ups and downs of a five-year plan."

The Rockies might be merrier, but they might not be a whole lot more successful unless they mine a few surprises from a patchwork rotation that will be without last year's ace (Ubaldo Jimenez, traded to the Indians last July) and, until this July, this year's presumptive one (lefthander Jorge De La Rosa, recovering from Tommy John surgery). "In every approximation I've seen, we're a fourth-place club," a still optimistic O'Dowd says. "And I get that, because of our pitching."

As of last July 6, when the embattled Dodgers were 14 games below .500, they seemed headed for a finish similar to that of the Rockies. But the performances of 23-year-old Cy Young winner Clayton Kershaw and Kemp enabled the club to finish in third place, at 82--79. Kemp led the league in home runs (39), RBIs (126), runs (115) and total bases (353), and his 10.0 WAR was the majors' best, according to the website Baseball Reference, since Barry Bonds's 12.4 in 2004. "Kemp, like, he was good," says Lincecum of the centerfielder's pre-2011 career. "Then he just separated himself from the rest of the pack."

General manager Ned Colletti made a creative attempt to give Kemp some hefty lineup protection by pursuing free-agent first baseman Prince Fielder. Despite the Dodgers' financial woes—cash-strapped owner Frank McCourt is in the process of selling the team—Colletti constructed a front-loaded, seven-year, $160 million offer that would have allowed the 27-year-old Fielder to opt out after the third or fourth year, potentially affording him a second opportunity to hit the open market while in his prime. But Fielder chose the security of the Tigers' nine-year, $214 million deal, leading Colletti to pin his hopes on modest contributions from such free agents as starters Chris Capuano and Aaron Harang, and infielders Mark Ellis and Jerry Hairston Jr., not to mention repeat seasons from Kemp and Kershaw. What might further elevate the Dodgers could be a return to form for the players who are arguably their third-, fourth- and fifth-most important—in some order, rightfielder Andre Ethier, first baseman James Loney and No. 2 starter Chad Billingsley—who each had down years in 2011.

The Diamondbacks improved by 29 wins from 2010 and won the division title due to a host of players who exceeded expectations. At age 26 righthander Ian Kennedy, who had never won more than nine games or finished with an ERA below 3.80, had a 2.88 ERA and was baseball's only 20-game winner other than Kershaw and AL Cy Young winner Justin Verlander. But it was Upton, who in his age 23 season set career highs in home runs (31), RBIs (88) and stolen bases (21), who put them over the top and led them to within a game of the NLCS. Still, says Upton, "Just making the first round of the playoffs is not as fun as most people think."

G.M. Kevin Towers attributes Upton's breakout—which came after a 2010 season that many considered disappointing, even though it included a .799 OPS at the age of 22—in part to the depth with which he suddenly found himself surrounded. Towers has further fortified the division's deepest roster by trading for A's righty Trevor Cahill—already, at 24, the winner of 40 games—and signing free-agent outfielder Jason Kubel.) "I think that was kind of the problem before Gibby [third-year manager Kirk Gibson] and I got here," says Towers, who took over as G.M. in September 2010. "[Upton] became at a very young age the face of the organization. Expectations were so high, he put a lot of added pressure on himself. That's why we brought in a lot of veteran players last year, to take that off him. I think we've only seen the tip of the iceberg with him."

For the Padres, the iceberg remains below sea level—but it is there, in the form of a solid young group that includes centerfielder Cameron Maybin and first baseman Yonder Alonso, who both turn 25 in April. "Not sure we can say these players are going to be All-Stars," says G.M. Josh Byrnes, "but we have some guys who have the chance."

In December, Byrnes dealt No. 1 starter Mat Latos to the Reds for a four-player package that included Alonso, who had an OPS of .833 in 117 career at bats for Cincinnati. Byrnes felt Alonso's all-fields hitting style would play better at capacious Petco Park than that of Anthony Rizzo, another top first base prospect whom the Padres dealt to the Cubs the next month. Maybin, who was named a Top 10 prospect by Baseball America in 2007, '08 and '09 but was dumped by the Marlins for a couple of San Diego relievers two Novembers ago, showed what he can do in 2011, stealing 40 bases while hitting nine homers and playing an excellent centerfield. "There's no doubt that Maybin has the skill set to become that guy," says manager Bud Black. "That's what we're hoping for."

The Padres' sights are mostly set on 2013 and beyond, when they will be more capable of competing with division-mates that have their Unexpendables locked up. Kemp, Posey, Tulowitzki and Upton are each under club control until at least 2015. "That is cool," says Tulowitzki, whose contract could extend to 2021. "That's huge for baseball, that all the big-market teams aren't getting some of these premier guys." This season, though, will belong to the Giants, who have a superior pitching staff and a healthy Posey. "It's almost like last year didn't happen," says Lincecum. "It's like, Buster's back to Buster." The Giants will be back too, in first place.

," says Mattingly. "Last year, when he was out, it changed 'em too." Posey's broken leg confirmed for the Giants what they had already suspected: They're sunk without him.

ROOKIE TO WATCH

YONDER ALONSO, PADRES

Alonso, 24, "kept hitting, kept hitting, kept hitting," as he says, in the Reds' organization, but was blocked at first base by Joey Votto. So he wasn't surprised to receive a call in December that he'd been traded. Call-ups in 2010 and '11 cost him ROY eligibility, but this is Alonso's first chance to make an impact.

STAR ON THE RISE

DEXTER FOWLER, ROCKIES

Called Snakeskin by Troy Tulowitzki for his lack of body fat, Fowler, 26, added 12 pounds of muscle over the off-season. That should help the centerfielder—who didn't start switch-hitting until he became a pro and who was rushed to the big leagues from Double A in 2008—come into his own at the plate.

STAR IN DECLINE

TODD HELTON, ROCKIES

The team values the 38-year-old for his ability to get on base (.385 OBP in 2011) and to grind out at bats. But his days as a premier slugger are behind him, says G.M. Dan O'Dowd. "The key with Todd is to understand the utilization of rest and recovery," he says. "It might be 100 games started, it might be 110."

THE PAYOFF PITCH ...

BEST CASE

A Buster Posey--led offense hits just enough to support a second-to-none—not even to the Phillies'—pitching staff. As it did in 2010, that formula takes San Francisco to the World Series.

WORST CASE

No one produces at the plate—not imports Melky Cabrera and Angel Pagan, not Aubrey Huff, not Brandon Belt, not even Posey. The Giants find themselves losing low-scoring affairs night after night after night.

BEST CASE

A roster with depth at every position save shortstop and catcher—top pitching prospect Trevor Bauer won't even start the year in the big leagues, even though he's ready—improves on last year's NLDS appearance.

WORST CASE

A bullpen that was a surprise in 2011 (3.71 ERA) regresses to its MLB-worst '10 form (5.74 ERA), and starters Ian Kennedy and Daniel Hudson don't repeat their '11 performances. A top 10 offense can't save them.

Kemp and Clayton Kershaw don't repeat their 2011 seasons—but Ethier (11 HRs) and Chad Billingsley (11--11, 4.21 ERA) do. That makes it impossible for the Dodgers to hang around in the wild-card race.

BEST CASE

After a down year in which G.M. Dan O'Dowd says "the game sped up on him," Carlos Gonzalez regains his MVP-caliber form. A surprisingly sturdy rotation led by lefty phenom Drew Pomeranz puts Colorado back into contention.

WORST CASE

O'Dowd's six 32-and-older imports contribute clubhouse leadership—and declining production, leaving Troy Tulowitzki to again try to win games by himself. That's something even he can't do.

BEST CASE

Newly acquired slugger Carlos Quentin—he has hit four fewer homers since 2008 than A-Rod—and a rotation buoyed by prospect Joe Wieland turn the Padres into a surprise contender, as they were in 2010.

WORST CASE

The Padres finish last, as expected, and centerfielder Cameron Maybin and first baseman Yonder Alonso see their development plateau—suggesting that a dark present will be matched by a dark future in San Diego.

PHOTOPhotograph by JOHN W. MCDONOUGHPHOTOJOHN G. MABANGLO/EPA

HATS OFF TO SF Nick Hundley's Padres have a growing core of up-and-coming talent, but not enough pop or experience to stand their ground against Pablo Sandoval and the Giants this year.